JP2017017319A - Substrate for semiconductor and mounting method for semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a semiconductor substrate having excellent heat radiation with high productivity for a substrate on which an LED chip or LED device in which large current flows is mounted.SOLUTION: Two main surfaces of an electrode pad 4 of copper are exposed, and the gap between two vertically adjacent electrode pads 4 is insulated by thermosetting white resin 8 on the same plane as the two main surfaces as shown in (a). Therefore, when the interval between the two electrode pads 4 is set to a distance at which the p, n electrodes of a flip chip type LED chip C1 can be mounted, the LED chip C1 can be mounted. When the LED chip C1 is sealed with transparent resin and diced and separated by a dotted line D, an LED device having an electrode terminal of a copper substrate is obtained. Even in a case of a wire bonding type LED chip, one electrode pad may be set as a die bonding pad and the other electrode pad may be set as a wire bonding pad. Furthermore, as shown in (b), since the lateral direction is conducted by a connection metal portion 5 thinner than the electrode pad, for example, an LED device having a protection element Z can be formed by using four electrode pads 4.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a semiconductor chip such as an LED chip or an LED device used for LED lighting, and a method for mounting the semiconductor chip on the substrate.

  In recent years, LED chips that carry a large current, LED devices using the same, and lighting devices using them have been put into practical use, and incandescent bulbs and fluorescent lamps as well as mercury lamps and halogen lamps are being replaced. With such widespread applications, semiconductor substrates with good heat dissipation for mounting LED chips and LED devices are becoming increasingly important.

A ceramic substrate with good thermal conductivity is often used as a semiconductor substrate for mounting an LED chip through which a large current flows to form an LED device. Alumina (Al ₂ O ₃ ) is generally used as the ceramic material, but the heat conductivity of a 3W class LED chip is about 21 W / mK and the plate thickness is reduced to about 0.3 mm. It is not enough to carry out. To compensate for this, copper via holes and inlays can be added, but the cost increases.

  In addition, aluminum nitride having a higher thermal conductivity, for example, 170 W / mK, can ensure sufficient heat dissipation, but this is also costly and dark in color. There is a disadvantage that it is not suitable.

  As a substrate for solving this problem, as shown in Patent Document 1, there is an example in which a collective substrate is formed of a copper plate and an epoxy resin. This is shown in FIG. As described in Patent Document 1, an unnecessary part is removed from a copper plate by a processing means such as etching to form a plurality of conductive members 60a, and an insulating member made of epoxy resin or the like in the gaps between the conductive members 60a The integrated substrate 60 filled with 60b is formed. Then, on the upper surface of the collective substrate 60, the collective circuit substrate 61 in which a large number of circuit boards having cutout holes 31c on which the LED chips are directly die-bonded on the conductive member is formed, positioned, thermocompression bonded, and integrated Turn into.

  The integrated substrate of the collective substrate 60 and the collective circuit substrate 61 is a substrate for a wire bonding type LED chip, and the copper conductive member is a die bond pad for heat dissipation, but the p and n electrode pads are collective. Arranged on the circuit board. In this integrated substrate, the LED chip is directly die-bonded to the copper conductive member via the Ag paste, so that the heat dissipation is extremely improved and the cost is reduced, but it can be used for the flip chip type LED chip. Absent.

  On the other hand, as a semiconductor (wiring) substrate on which an LED device that conducts a large current is mounted, a metal base substrate having a moderate heat dissipation property used in a lighting device is widely used. As the metal, copper or aluminum having good thermal conductivity is generally used, but there is also one using iron in terms of cost. Aluminum is most often used in terms of thermal conductivity and cost.

  The aluminum base substrate has a structure in which an insulating layer having a thickness of approximately 0.1 mm is formed on an aluminum plate having a thickness of approximately 1.5 mm, and a wiring pattern is formed on the copper having a thickness of 30 to 80 μm. Therefore, good heat dissipation is determined by the thermal conductivity and thickness of the insulating layer and the thickness of the copper wiring pattern. In consideration of cost, an insulating layer having a thickness of 80 μm, a thermal conductivity of 5 W / mK, and a copper wiring pattern having a thickness of 35 μm is generally used.

  However, in this prior art, the heat generated in the LED device mounted on the pair of electrode pads formed by the copper wiring pattern of the aluminum base substrate is transferred from the electrode pad to the aluminum plate through the insulating layer. An insulating layer with poor conductivity is a bottleneck.

JP 2004-146411 A

  As a semiconductor substrate for mounting an LED chip that allows a large current to flow into an LED device, the integrated substrate of Patent Document 1 described above is directly die-bonded to a copper conductive member via an Ag paste. The heat dissipation (the thermal conductivity of copper and Ag paste is 391 W / mK and 95 W / mK) is extremely good and the cost is low, but there is a problem that it cannot be used for a flip chip type LED chip.

  In addition, the above-mentioned aluminum base substrate used as a semiconductor (wiring) substrate for mounting an LED device through which a large current flows is a bottleneck due to the thermal conductivity (5 W / mK) of the insulating layer, and the aluminum has a very good thermal conductivity. There is a problem that the rate is not fully utilized.

  The object of the present invention is to effectively utilize the extremely good thermal conductivity of metal, such as a flip chip type LED chip, a wire bonding type LED chip, and an LED device. A semiconductor substrate capable of effectively dissipating heat generated in all semiconductor components and a method for mounting a chip on the semiconductor substrate are provided.

  The semiconductor substrate according to the present invention is a plate-shaped metal having a thickness t, which includes an electrode pad region in which a plurality of electrode pads for mounting a semiconductor chip or a semiconductor device are formed, and a frame region surrounding the electrode pad region. A frame is connected between electrode pads adjacent to each other in one direction in the electrode pad region, and between the electrode pad region and the frame region by a connecting metal portion having a thickness less than t, Two main surfaces are exposed, and the space of the electrode pad region is filled with a thermosetting resin, and the thermosetting resin connects electrode pads adjacent to each other in an orthogonal direction orthogonal to the one direction. The electrode pad region is formed so as to be substantially flush with the two principal surfaces of the electrode pad so as to substantially fill the space.

  According to the above configuration, the electrode pad is formed by a metal (for example, copper) frame having a thickness t, the two main surfaces of the electrode pad are exposed, and the two main pads are disposed between the two electrode pads in the orthogonal direction. Since it is insulated with a thermosetting resin that is flush with the surface, if the distance between the two electrode pads is set such that the p-electrode and n-electrode of the flip-chip type LED chip can be mounted, the flip A chip-type LED chip can be mounted. Of course, even in the case of a wire bonding type LED chip, one electrode pad may be a die bond pad and the other electrode pad may be a wire bonding pad. However, the copper frame surface needs to be plated suitable for the mounting method. Then, if the LED chip is mounted on one of the two main surfaces of the exposed electrode pad, the heat generated in the LED chip can be obtained by using the other main surface as the electrode terminal surface to the external substrate. Then, heat can be efficiently radiated to the external substrate through copper having extremely good thermal conductivity.

  Furthermore, the adjacent electrode pads are connected in one direction with a thickness less than the thickness t, for example, a rectangular copper connecting metal portion, and the orthogonal direction is connected with a thermosetting resin. When the pad becomes one LED device, the separation and individualization can be efficiently performed by dicing. The reason is that the copper connection metal portion has a rectangular shape thinner than t, and therefore the periphery of the connection metal portion is surrounded by a thermosetting resin. Therefore, even if it is difficult to cut by dicing with copper alone, there is a dressing effect with a thermosetting resin, so that copper can be cut easily.

  Further, in the case of a semiconductor (wiring) substrate on which an LED device is mounted, a plurality of electrode pads, a connecting metal portion that connects the electrode pads in the one direction, and a thermosetting resin that connects the electrode pads in the orthogonal direction; Thus, by forming the wiring pattern, it is possible to obtain a wiring board with good heat dissipation that effectively utilizes the extremely good thermal conductivity of copper.

  In the semiconductor substrate of the present invention, the electrode pads adjacent to each other in the orthogonal direction of the electrode pad region are also partially connected by a connecting metal portion thinner than the thickness t.

  According to the above configuration, in the plate-shaped metal frame having the thickness t in which the electrode pad region and the frame region are formed by a method such as etching, a plurality of the electrode pads formed are Since only the rectangular connecting metal portions thinner than the thickness t in the direction are connected, the shape tends to be distorted in the orthogonal direction until the thermosetting resin is filled. Therefore, it can be reinforced by partially connecting with the connecting metal portion also in the orthogonal direction. However, when the connecting metal portions are connected in the orthogonal direction, the connected electrode pads are electrically connected, and therefore, it is necessary to design in consideration thereof or to be regarded as a part of the frame region.

  The reason why the thickness of the connecting metal portion in the one-direction and partially formed in the orthogonal direction is made thinner than t is that the reason comes from the method for manufacturing a semiconductor substrate, which will be described later, and the dressing effect works effectively. This is an important technique for creating a structure that can be separated by a dicer.

  In the semiconductor substrate of the present invention, the semiconductor chip is a flip-chip type LED chip having a pair of p-electrode and n-electrode on substantially the same surface, and the thermosetting resin in the electrode pad region. A plurality of pairs of p-electrode pads and n-electrode pads of the LED chip connected by a thermosetting white resin, which is a matrix, are formed in a matrix, and of the two main surfaces of the p-electrode pads and the n-electrode pads, One main surface is a mounting surface for mounting the LED chip, and the other main surface is an electrode terminal surface for mounting on an external substrate.

  According to the above configuration, since the electrode pad in the electrode pad region corresponds to the pair of electrodes of the flip chip type LED chip, the flip chip type LED chip can be mounted, and the pair of electrode pads Is connected to the thermosetting white resin with a connecting metal part in a matrix, so that it can be easily separated with a dicer and has an electrode pad with extremely good thermal conductivity of metal (for example, copper) However, a plurality of them can be easily created.

  In the semiconductor substrate of the present invention, the semiconductor device is an LED device having a pair of p-electrode terminals and an n-electrode terminal, and the electrode pad region includes a plurality of the electrode pads and the one-way connection metal portion. And a wiring pattern is formed with the thermosetting white resin which is the thermosetting resin in the orthogonal direction.

  According to the above configuration, the electrode pads adjacent to each other in the orthogonal direction are connected by an insulating thermosetting white resin, so that insulation is maintained, so that LED devices can be connected in series, The electrode pads adjacent in one direction are in a conductive state unless the connection metal portion is cut, and the LED devices can be connected in parallel. Therefore, an efficient wiring pattern can be realized by selectively cutting the connecting metal portion. Furthermore, it is possible to obtain a wiring board with good heat dissipation that effectively utilizes the extremely good thermal conductivity of copper.

  In the semiconductor substrate of the present invention, the pair of electrode pads have a convex cross-sectional shape, and the area of the mounting surface is substantially the same as the electrode surface of the flip chip type LED chip, and the electrode terminals It is narrower than the area of the surface, and the periphery of the mounting surface is covered with the thermosetting white resin.

  According to the above configuration, when the flip chip type LED chip is mounted with solder, there is a problem that if the mounting surface has a large area, the LED chip moves when the solder is melted and good electrical connection cannot be made. easy. Therefore, it is preferable that the mounting surface is approximately the same as the electrode surface of the LED chip, and the periphery is covered with the thermosetting white resin in which molten solder is difficult to spread. Further, the surface of the electrode pad is plated with Au, Ag, or Sn, which is easy to adapt to the solder, but it is more stable and has better reflectivity when coated with a thermosetting white resin mixed with titanium oxide powder. It becomes a surface.

  In the semiconductor substrate of the present invention, the plate-shaped metal frame is made of copper or aluminum, and the thickness t is 0.1 mm or more and 1.5 mm or less.

  According to said structure, copper and aluminum are suitable as a material with favorable heat conductivity as a metal and cheap. The thermal conductivity of copper is 391 W / mK, the aluminum is 222 W / mK, and copper is optimal. The thickness is limited by the distance between the electrode pads, and the fine pattern is formed by a photolithographic etching method, but the electrode pad region and the frame region are formed except for an excess portion of the plate-like copper frame. The minimum distance between the electrode pads is about the same as the thickness t. Therefore, when the plate thickness is 0.1 mm, the minimum distance between the electrode pads is 0.1 mm. Considering this, the thickness of the copper frame for a 3W class LED chip is optimally about 0.2 mm, and the thickness of the copper frame for a 3W class LED device is 0.5 mm to 1.5 mm. Degree. In order to maintain the shape while making the connecting metal portion thinner than the plate thickness t, the plate thickness t is preferably 0.1 mm or more.

  In the semiconductor substrate of the present invention, the thermosetting resin is a thermosetting white resin in which a titanium oxide powder is mixed with an epoxy resin or a silicon resin.

  According to said structure, there is little discoloration by a heat | fever, it has the hardness and adhesiveness which hold | maintain an electrode pad, and a curvature does not generate | occur | produce. In addition, by reflecting the photocatalytic properties generated by the blue LED light by coating or siloxane treatment, titanium oxide powder with good reflectivity is mixed with epoxy resin or silicon resin to produce a thermosetting white resin. The rate will also improve.

  In the semiconductor substrate of the present invention, two or more A holes for alignment are formed in the frame region.

  According to the above configuration, the mounting of the LED chip on the semiconductor substrate can be performed using a jig such as an alignment plate in which two or more pins that fit into the alignment A hole are erected. , It can be used for alignment when manufacturing LED devices.

  Preferably, in the method for manufacturing a semiconductor substrate, heat resistance in which a vent hole for venting the electrode pad region is formed on one main surface of the two main surfaces of the plate-like metal frame. Air is extracted from the space of the electrode pad region of the plate-shaped metal frame by the A1 step of attaching the plastic sheet and the heat-resistant plastic sheet without the vent on the other main surface, and the path of the vent. A2 step, A3 step of filling the space portion of the electrode pad region of the plate-like metal frame with the thermosetting resin using atmospheric pressure in the path of the vent hole, and filling the thermosetting resin And A4 step of curing with heat and peeling off the heat-resistant plastic sheet.

  According to said structure, the board | substrate for semiconductors of this invention can be manufactured easily with simple equipment. That is, the electrode pad region is sealed except for the vent hole by a frame region of the plate-like metal frame and a heat-resistant plastic sheet pasted on two main surfaces of the plate-like metal frame (step A1). ). Then, air is extracted from a space portion in the sealed electrode pad region using a rotary pump in a path through which the thermosetting resin passes from the vent hole (step A2). In this state, air is evacuated for about 10 to 20 minutes. Thereafter, the valve on the rotary pump side is closed and gradually returned to atmospheric pressure. In this process, the space of the electrode pad region is filled with the thermosetting resin at atmospheric pressure (step A3). Next, for example, the filled thermosetting resin is cured under conditions of 150 ° C. for 1 hour, and finally, the heat-resistant plastic sheet is peeled off to complete a semiconductor substrate (step A4).

  Preferably, after the step A4, a step C1 of selectively cutting the connecting metal portion connecting the electrode pads adjacent in the one direction in the electrode pad region with a dicer to form a wiring pattern. It is characterized by adding.

  According to said structure, the connection metal part which has connected the electrode pad adjacent to the said one direction of the said electrode pad area | region is selectively cut | disconnected with a dicer, and the said one electrode which is not cut | disconnected with the said several electrode pad. An efficient wiring pattern can be formed by the connecting metal portion in the direction and the thermosetting resin that connects the electrode pads in the orthogonal direction.

  The LED chip mounting method on the semiconductor substrate according to the present invention is a method for mounting the LED chip on the semiconductor substrate, wherein a pair of p-electrode pad and n-electrode pad is provided in the electrode pad region. Using the semiconductor substrate in which a plurality of A holes for alignment are formed in the frame region and two or more A holes for alignment are formed on the pair of p electrode pads and n electrode pads, B1 process of applying solder paste, and using a square frustum-shaped LED chip as the LED chip, a rectangular hole that is larger than the top surface of the square frustum-shaped LED chip and smaller than the bottom surface has the pair of p electrode pads and A plurality of rectangular holes formed in a matrix at the same pitch as the n-electrode pad and two or more B holes at substantially the same size as the A holes for alignment of the semiconductor substrate. However, using the formed metal mask, the square pyramid shaped LED chip is inserted into the rectangular hole of the metal mask from the upper surface, and the upper surface of the LED chip is temporarily fixed with an adhesive tape, and aligned in a matrix. Step B2 and the pair of p-electrodes coated with the semiconductor substrate solder paste using an alignment jig in which two or more pins are fitted to the alignment A hole and B hole. The alignment pins are placed on the pins so that the pad surfaces of the pads and the n-electrode pad and the p-electrode surface and the n-electrode surface of the square pyramid-shaped LED chip aligned with the metal mask face each other. A plurality of the square pyramid-shaped LED chips are formed on the plurality of electrode pad surfaces on which the adhesive tape is peeled off and the solder paste of the semiconductor substrate is applied. And B5 step of electrically connecting the square pyramid-shaped LED chips placed on the semiconductor substrate by applying heat and melting the solder paste. It is characterized by that.

  According to said structure, using the shape of the truncated pyramid of the LED chip, a simple jig tool, that is, an alignment jig in which two or more pins that fit into the A hole and the B hole are erected, Using the rectangular hole and the metal mask having the B hole, LED chips having fine pattern electrodes can be collectively mounted on the semiconductor substrate.

  As described above, the semiconductor substrate and the method for mounting the chip on the semiconductor substrate of the present invention effectively utilize the extremely good thermal conductivity of the metal, and the flip chip type LED chip, the wire bonding type LED chip, Is a substrate with good heat dissipation when a semiconductor device is manufactured by mounting a semiconductor chip such as a diode as well as an LED. In that case, a semiconductor device can be efficiently manufactured by a dicer.

   In addition, the semiconductor substrate of the present invention can be a wiring board with good heat dissipation for mounting a semiconductor device (particularly an LED device). At that time, an efficient wiring pattern can be formed by a dicer.

It is (a) top view and (b) sectional drawing of VV of the whole figure of the plate-shaped metal frame used for the board | substrate for semiconductors of this invention. It is a fragmentary view of the substrate for semiconductors of the present invention. It is the fragmentary view which mounted the semiconductor chip on the board | substrate for semiconductors of this invention. It is the (a) top view and (b) WW sectional drawing of the fragmentary figure of the plate-shaped metal frame used for the board | substrate for semiconductors of this invention. It is a fragmentary view of the substrate for semiconductors of the present invention. It is the fragmentary view which mounted the LED chip on the board | substrate for semiconductors of this invention. It is the (a) top view and (b) sectional drawing of XX of the fragmentary figure of the board | substrate for semiconductors of this invention. 1 is an overall view of a plate-shaped metal frame used for a semiconductor substrate of the present invention. It is a fragmentary figure of the plate-shaped metal frame used for the board | substrate for semiconductors of this invention. It is the fragmentary figure of the board | substrate for semiconductors of this invention, (a) The top view before dicing and (b) The top view after dicing. It is the (a) top view and (b) circuit diagram which mounted the LED device on the board | substrate for semiconductors of this invention. It is a figure for demonstrating the manufacturing method of the board | substrate for semiconductors of this invention. It is a figure for demonstrating the method of mounting an LED chip on the board | substrate for semiconductors of this invention. It is a perspective view of the conventional semiconductor substrate.

   Hereinafter, embodiments of a semiconductor substrate of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

Example 1
First, a schematic view of a plate-shaped metal frame used for a semiconductor substrate of the present invention is shown in FIG.

 (A) is a top view, (b) is sectional drawing of VV.

  This plate-shaped metal frame is a copper frame 1 using a JIS standard H3100 C1100P copper plate material having a thickness t of 0.2 mm. A pattern is formed by photolithography and etching. The electrode pad region 2 includes a plurality of electrode pads 4 formed in a matrix, and a frame region 3 surrounding the electrode pad region 2. The thicknesses of the electrode pad 4 and the frame region 3 are the same as the plate thickness. 2 mm. The electrode pads 4 adjacent in the horizontal direction are connected by a rectangular connection metal portion 5 having a thickness of 0.1 mm. The frame region 3 has two A holes 6 for alignment. The diameter of the hole is about 3 mm. One hole A may be a long hole. The electrode pad region 2 and the frame region 3 are also connected by a connecting metal portion 5 in the horizontal direction.

  A space portion of the electrode pad region 2 of the copper frame 1 is filled with a thermosetting white resin 8. The manufacturing method will be described with reference to the drawings shown in FIGS.

  First, FIG. 12A prepares the copper frame 1 shown in FIG. 1 in which a pattern is formed by removing a surplus portion by photolithography and etching.

  Next, FIG. 12B shows a heat-resistant plastic sheet 72 a having a vent hole 71 communicating with the electrode pad region 2 on the upper surfaces of the two main surfaces of the copper frame 1. Affix it where it can ventilate. A dedicated port may be formed in the frame region 3 as in the notch 53 of FIG. Further, a heat-resistant plastic sheet 72b having no air holes is attached to the bottom surfaces of the two main surfaces. As a result, the space portion of the electrode pad region 2 is sealed except for the air holes 71.

  Next, as shown in FIG. 12 (c), a double-sided tape having a hole of almost the same size as the vent hole 71 is pasted on the vent hole 71 on the heat-resistant plastic sheet 72a in accordance with the hole position, On top of that, a hole having substantially the same size is formed on the bottom surface, and a transparent cylindrical container 73 having an open top surface is attached and set with the hole positions aligned. Next, about 5 g of the defoamed thermosetting white resin 8 is placed in the transparent cylindrical container 73 to prepare a resin-filled workpiece 70. As for the thermosetting white resin used here, titanium oxide powder is mixed with silicon resin in an amount of 20% of the total amount by weight ratio.

  Next, as shown in FIG. 12 (d), the resin-filled workpiece 70 is placed in the vacuum chamber 75, the valve V1 is opened, V2 is closed, and the rotary pump (not shown in the figure) is used for vacuuming. The air in the chamber 75 is evacuated. As a result, the air in the space within the sealed electrode pad region 2 passes through the vent hole 71 and through the thermosetting white resin 8. In this state, air is removed for about 15 minutes.

  Next, as shown in FIG. 12E, the valve V1 on the rotary pump side is closed, and V2 is slowly opened to gradually return to the atmospheric pressure. In this process, the thermosetting white resin 8 is filled in the space of the electrode pad region 2 at atmospheric pressure.

  Next, as shown in FIG. 12 (f), the transparent cylindrical container 73 is removed, and the filled thermosetting white resin 8 is cured at 150 ° C. for 1 hour under the condition of the workpiece 70. The heat-resistant plastic sheets 72a and 72b are peeled off to complete the semiconductor substrate.

  A partial view of the semiconductor substrate 10 manufactured by the above method is shown in FIG. A space portion of the electrode pad region 2 is filled with the thermosetting white resin 8. Since the connecting metal portion 5 is thin, the thermosetting white resin 8 is placed on the connecting metal portion 5 and is flush with the electrode pad 4.

  This figure also shows a connecting metal portion 7 that connects the adjacent ones of the electrode pads 4 in the vertical direction. This is because a plurality of the electrode pads 4 formed on the copper frame 1 are connected only in the lateral direction by a rectangular connection metal portion 5 thinner than the thickness t. This is because the shape tends to be distorted in the vertical direction until filling. It can be reinforced by partially connecting with the connecting metal part 7 also in the vertical direction. However, if the connecting metal portions 7 are connected in the vertical direction, the connected electrode pads 4 are electrically connected, and thus cannot be used for the device.

  The reason why the connecting metal portions 5 and 7 are made thinner than the plate thickness t is important for making the space portion of the sealed electrode pad region 2 into one space region in FIG. Since the element does not separate the space, the thermosetting white resin 8 is filled to every corner.

  Next, a mode in which a semiconductor chip, particularly an LED chip is mounted on the semiconductor substrate 10 will be described with reference to FIG.

  In the case of FIG. 3A, the two main surfaces of the electrode pad 4 are exposed, and between the two vertically adjacent electrode pads 4 is a thermosetting white resin 8 flush with the two main surfaces. Since it is insulated, the flip chip type LED chip C1 can be mounted by setting the distance between the two electrode pads 4 to a distance that allows the p electrode and the n electrode of the flip chip type LED chip C1 to be mounted. . As shown in FIG. 3A, Genesis Corporation can be used as a flip chip type LED chip C1 divided into a p-electrode and an n-electrode at the center of the LED chip C1. If it seals with transparent resin and dicing isolation | separation by the dotted line D, it will become an LED device with the electrode terminal of a copper substrate. Of course, even a wire bonding type LED chip can be mounted if one electrode pad is a die bond pad and the other electrode pad is a wire bonding pad.

  Further, as shown in FIG. 3 (b), the lateral direction is conducted by the connecting metal portion 5, and therefore, for example, an LED device including a Zener diode Z as a protective element is also used by using four electrode pads 4. it can.

(Example 2)
As a next embodiment, a semiconductor substrate 20 suitable for manufacturing an LED device using a flip chip type square pyramid shaped LED chip will be described.

  FIG. 4 shows a partial view of a plate-like copper frame 30 used for this. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along the line W-W. The thickness t of the copper frame 30 is about 0.2 mm.

  The electrode pad 34 in the electrode pad region 2 of the copper frame 30 is a pair of electrode pads (p electrode pad and n electrode pad) formed to correspond to a pair of electrodes (p electrode and n electrode) of the LED chip. Consists of. Since the horizontal direction is connected by the connection metal part 5 and the vertical direction is short-circuited, the electrode pads forming a pair are not connected, but the adjacent electrode pads are connected by the connection metal part 7. The structure is strong against distortion.

  FIG. 5 shows a semiconductor substrate 20 in which the copper frame 30 is filled with the thermosetting white resin 8. Although not shown in FIG. 5, two A holes 6 for alignment are formed in the frame region 3 in the same manner as in FIG. 1. The diameter of the A hole 6 is about 3 mm. A plurality of LED chips can be collectively mounted on the semiconductor substrate 20 by using the alignment A hole 6 and the shape of the LED chip having a quadrangular pyramid shape. The mounting method will be described with reference to the schematic diagrams shown in FIGS.

  First, the semiconductor substrate 20 shown in FIG. 5 filled with the thermosetting white resin 8 as shown in FIG. 13A is prepared, and the pair of electrode pads (p electrode pad and n electrode pad) 34 are mounted. A solder paste 81 is applied on the surface 34a.

  Next, as shown in FIG. 13B, a rectangular hole 83 larger than the upper surface (light emitting surface) and smaller than the bottom surface (electrode surface) of the LED chip C2 having a truncated pyramid shape is formed with the pair of electrode pads 34. A plurality of metal masks 80 are formed in a matrix at the same pitch, and two B holes 84 having substantially the same size are formed at substantially the same positions as the A holes 6 for alignment of the semiconductor substrate 20. The square pyramid shaped LED chip C2 is inserted into the rectangular hole 83 of the metal mask 80 from the upper surface, and the upper surface of the LED chip C2 is temporarily fixed with an adhesive tape 85 and aligned in a matrix.

  Next, as shown in FIG. 13 (c), the pin 86 fitted into the A hole 6 and the B hole 84 is positioned using two positioning jigs 87 and the punching plate 87a of the jig 87 is removed. Further, the solder paste 81 side applied to the pair of electrode pads 34 from the semiconductor substrate 20 and the electrode surface (bottom surface) side 82a of the LED chip C2 aligned with the metal mask 80 are p. The A hole 6 and the B hole 84 for alignment are overlapped with the pin 86 so as to face each other like the electrode pad and the p electrode and the n electrode pad and the n electrode.

  Next, as shown in FIG. 13D, the adhesive tape 85 is peeled off, and a chip pressing jig 88 is placed on top of each other, and the LED chip C2 is pressed by its own weight.

  Next, as shown in FIG. 13E, the metal mask 80 is lifted up slightly while the LED chip C2 is pressed by the chip pressing jig 88, and the metal mask 80 is separated from the LED chip C2. The mask 80 is lifted together with the chip pressing jig 88, and the plurality of square pyramid shaped LED chips C2 are mounted on the mounting surfaces 34a of the plurality of electrode pads coated with the solder paste 81 of the semiconductor substrate 20. Put them all together.

  Next, as shown in FIG. 13 (f), together with the punching plate 87a, the semiconductor substrate 20 on which the LED chip C2 is mounted is taken out, heated in a reflow furnace, and the solder paste 81 is melted. The square frustum-shaped LED chip C2 placed on the semiconductor substrate 20 is electrically connected.

  The biggest reason why this mounting method is possible is that the arrangement pitch of the electrode pads 34 of the copper frame 30 manufactured with high precision by photolithography and etching is filled and cured with the thermosetting white resin 8, as shown in FIG. In the case of the semiconductor substrate 20 shown, the arrangement pitch hardly changes. For this purpose, it is preferable to use an elastic silicon resin as the thermosetting white resin 8. Epoxy resins of a variety that do not warp can also be used.

  FIG. 6 shows a partial view of the semiconductor substrate 20 on which the LED chip C2 is mounted by the above method. A pair of p and n electrode pads 34 are insulated by a thermosetting white resin 8. As such a flip chip type LED chip C2 having a truncated pyramid shape, for example, one manufactured by Cree can be used. If it seals with transparent resin and dicing isolation | separation by the dotted line D, it will become an LED device with the electrode terminal of a copper substrate.

  Further, when the LED chip C2 is mounted and reflowed, if the solder paste is not appropriate, the LED chip C2 may move (displace) due to the surface tension of the melted solder, resulting in a mounting failure. In order to prevent this, as shown in FIG. 7, the cross-sectional shape of the pair of electrode pads 44 is convex, the area of the LED chip mounting surface 44a is narrower than the area of the electrode terminal surface 44b, and the LED chip C2 The area of the electrode surface may be approximately the same or slightly wider, and the periphery thereof may be covered with the thermosetting white resin 8. In addition, in this structure, if a white resin in which a titanium oxide having a good reflectance is mixed with the thermosetting white resin 8 is used, the luminance can be improved when an LED device is used.

(Example 3)
As a next embodiment, a semiconductor substrate 52 suitable for a wiring board on which an LED device is mounted will be described.

  FIG. 8 is a schematic view showing the entire plate-like copper frame 50 used for this, and the partial region 51 is described in detail in the partial view of FIG. The partial area 51 is referred to as a unit copper frame 51. That is, it is a unit copper frame used for one LED illumination (LED lamp or the like).

  The plate-like copper frame 50 has a thickness t of 0.3 mm to 0.5 mm. Although thicker is better for heat dissipation, it is limited by the size of the LED device.

  As shown in FIG. 8, a plurality of unit copper frames 51 are formed in a matrix in the electrode pad region 2. The divided metal portion 57 that vertically divides the electrode pad region 2 is also a kind of the vertical connecting metal portion 7 and has a rectangular shape that is thinner than the plate thickness t.

  As shown in FIG. 9, the unit copper frame 51 includes a plurality of electrode pads 54 having different sizes. The horizontal connecting metal portion 55 also has a different size, and the wide connecting metal portion 55a is one of the elements constituting the wiring pattern.

  FIG. 10A shows a wiring board 52 in which the unit copper frame 51 is filled with the thermosetting white resin 8. When the partial region 51 is separated for the one LED illumination, all of the thin horizontal connecting metal portions 55 are cut by a dicer (63 pieces are shown in the drawing), and the wide connecting metal portion 55a is ( The figure remains 8) (eight are shown). These connecting metal portions 55 and 55a are arranged so as to facilitate selective cutting with a dicer. FIG. 10B shows the wiring substrate 52 after the thin connecting metal portion 55 is cut by dicing, and the periphery of the wiring substrate 52 is returned to the horizontal connecting metal portion 55 and the thermosetting white resin 8 with a dicer. Although it is fully cut, the horizontal connecting metal portion 55 in the wiring board 52 is not shown, but the connecting metal portion 55 is cut by half-cutting with a dicer from the back side of the drawing. ing.

  FIG. 11A shows a structure in which 20 LED devices L are mounted on the wiring board 52. From the wiring pattern of FIG. 11A, as shown in FIG. 11B, a circuit in which ten LED devices L are connected in series is a circuit including two circuits. The wiring board 52 includes a copper electrode pad having a thickness of 0.3 to 0.5 mm, a thermosetting white resin 8 that is mechanically connected while electrically insulating them, and the electrode pad. It is comprised with the connection metal part connected electrically. Therefore, the heat generated in the LED device L is transferred to the copper electrode pad having excellent heat conduction and easily flows downward. Therefore, if a heat sink is arranged under the wiring board 52, the LED device L can be concentrated in the center, and is optimal for LED lamps of point light sources that do not allow multiple shadows.

DESCRIPTION OF SYMBOLS 1,30,50 Plate-shaped copper (metal) frame 10,20,40 Semiconductor substrate 2 Electrode pad area | region 3 Frame area | region 34,44 A pair of electrode pad 34a Mounting surface 4,54 Electrode pad 5,55 Connection metal part 51 Unit copper frame 52 Wiring board 53 Notch 57 Divided metal part 6 A hole 7 Vertical connecting metal part 70 Resin-filled work 71 Ventilation holes 72a, 72b Heat-resistant plastic sheet 73 Transparent cylindrical container 75 Vacuum chamber 8 Thermosetting white resin 80 Metal Mask 81 Solder Paste 82a Electrode Surface 83 Rectangular Hole 84 B Hole 85 Adhesive Tape 86 Pin 87 Positioning Jig 87a Die Plate 88 Chip Holding Jig C1, C2 LED Chip D Dicing Line Z Zener Diode L LED Device

Claims (7)

An electrode pad for mounting a semiconductor chip or a semiconductor device is a plate-shaped metal frame having a thickness t composed of a plurality of formed electrode pad regions and a frame region surrounding the electrode pad region. The electrode pads adjacent to each other in one direction in the region, and the electrode pad region and the frame region are connected by a connecting metal portion thinner than the thickness t,
The two main surfaces of the electrode pad are exposed, and the space of the electrode pad region is filled with a thermosetting resin, and the thermosetting resin is between the electrode pads adjacent to each other in the orthogonal direction perpendicular to the one direction. The semiconductor substrate is formed so as to substantially fill a space in the electrode pad region so as to be substantially flush with the two main surfaces of the electrode pad.   2. The semiconductor substrate according to claim 1, wherein electrode pads adjacent to each other in the orthogonal direction of the electrode pad region are also partially connected by a connecting metal portion having a thickness less than t. The semiconductor chip is a flip chip type LED chip having a pair of p-electrode and n-electrode on a substantially flush surface,
In the electrode pad region, a plurality of pairs of p electrode pads and n electrode pads of the LED chip connected with the thermosetting white resin that is the thermosetting resin are formed in a matrix,
Of the two main surfaces of the p-electrode pad and the n-electrode pad, one main surface is a mounting surface when mounting the LED chip, and the other main surface is an electrode terminal surface when mounting on the external substrate. 3. The semiconductor substrate according to claim 1, wherein the substrate is a semiconductor substrate.   3. The semiconductor substrate according to claim 1, wherein the plate-shaped metal frame is made of copper or aluminum and has a thickness t of 0.1 mm or more and 1.5 mm or less.   3. The semiconductor substrate according to claim 1, wherein the thermosetting resin is a thermosetting white resin in which a titanium oxide powder is mixed with an epoxy resin or a silicon resin.   4. The semiconductor substrate according to claim 1, wherein two or more A holes for alignment are formed in the frame region. A method for mounting an LED chip on a semiconductor substrate according to any one of claims 1 to 6,
A plurality of pairs of p-electrode pads and n-electrode pads formed in a matrix in the electrode pad region, and the semiconductor substrate in which two or more A holes for alignment are formed in the frame region; B1 step of applying a solder paste on the pair of p electrode pads and n electrode pads,
A rectangular frustum-shaped LED chip is used as the LED chip, and rectangular holes larger than the top surface of the square frustum-shaped LED chip and smaller than the bottom surface are arranged at the same pitch as the pair of p-electrode pads and n-electrode pads. A metal mask in which a plurality of rectangular holes formed in a shape and two or more B holes having substantially the same size and the same positions as the A holes for alignment of the semiconductor substrate are formed. B2 step of using the square pyramid shaped LED chip from the upper surface into the rectangular hole of the metal mask, temporarily fixing the upper surface of the LED chip with an adhesive tape, and aligning in a matrix,
The pair of p-electrode pads and n-electrodes, to which the solder paste for the semiconductor substrate is applied, using an alignment jig in which two or more pins are fitted to the alignment A holes and B holes. The A hole and B for alignment are provided on the pin so that the pad surface of the pad and the p electrode surface and the n electrode surface of the square pyramid-shaped LED chip aligned with the metal mask face each other. B3 process to pile up through the hole,
B4 step of peeling the adhesive tape and placing the plurality of square frustum-shaped LED chips together on the plurality of electrode pad surfaces coated with the semiconductor substrate solder paste;
B5 step of electrically connecting the square pyramid-shaped LED chip placed on the semiconductor substrate by applying heat and melting the solder paste, on the semiconductor substrate LED chip mounting method.

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